Effects of macrophage colony-stimulating factor on the proliferation and the function of Kupffer cells

Using flow cytometric methods, the influence of recombinant human macrophage colony-stimulating factor (rhM-CSF) on DNA synthesis, the phagocytosis of microspheres and the uptake of lipopolysaccharide (LPS) in cultured rat Kupffer cells was investigated. Incubation with 10(3) U/ml of rhM-CSF did not increase the S-phase population of Kupffer cells, however, 10(5) U/ml of M-CSF significantly increased that population from 6.26 +/- 0.68% to 8.31 +/- 0.99%. Significantly increased rate of cells phagocytosing microspheres was provoked by rhM-CSF at concentration higher than 10(3) U/ml. Uptake indexes at concentrations of 10(3), 10(4), 10(5), and 10(6) U/ml of rhM-CSF were 114.2 +/- 7.7, 116.5 +/- 8.7, 117.5 +/- 9.1, and 120.0 +/- 11.5, respectively. Significantly increased rate of cells stained with fluorescent LPS was provoked by rhM-CSF at concentrations higher than 10(5) U/ml. Uptake indexes at concentrations of 10(5) and 10(6) U/ml were 115.2 +/- 6.4 and 118.0 +/- 4.3, respectively. These results indicate that M-CSF has a potency to stimulate DNA synthesis, phagocytic activity, and LPS uptake of mature Kupffer cells in vitro. This potency may be helpful to the enhancement or the recovery of the role of Kupffer cells, which is a part of the host defense mechanism, in diseased states.